Subtract 10 or 100 from a Three-Digit Number: Step-by-Step Example
30 October 2026
When your child learns to subtract 10 or 100 from a three-digit number, it helps them work out answers quickly in their head. This skill is useful for mental maths and builds confidence for the 11+ exam.
Example question
Subtract 100 from 427.
Step 1: Look at the hundreds digit in 427, which is 4.
Step 2: Subtract 1 from the hundreds digit (4 - 1 = 3).
Step 3: Keep the tens digit (2) and the ones digit (7) the same.
The answer is 327.
After seeing this example, your child will spot the pattern in how the digits change when subtracting 100. They can now try similar questions and practise this method with other three-digit numbers.
